Seals for surgical access assemblies

ABSTRACT

Access assemblies includes an instrument valve housing and a valve assembly disposed within the cavity of the instrument valve housing. The valve assembly includes a guard assembly, a seal assembly disposed adjacent to the guard assembly, and a centering mechanism for maintaining the seal assembly and guard assembly centered within a cavity of the instrument valve. In embodiments, the seal assembly includes a plurality of seal sections that are movable from an unfolded configuration to folded configuration in which the seal assembly forms a hexagonal member defining an opening to facilitate sealed passage of a surgical instrument. The seal sections may include a tapered inner edge for engaging a surgical instrument inserted through the instrument valve housing.

BACKGROUND Technical Field

The present disclosure relates to access assemblies for minimallyinvasive surgery, including seals. More particularly, the presentdisclosure relates to seals for surgical access assemblies.

Background

In order to facilitate minimally invasive surgery, a working space mustbe created in the desired surgical space. An insufflation gas, typicallyCO₂, is introduced into the abdomen of the patient to create an inflatedstate called a pneumoperitoneum. Access assemblies are utilized to allowthe introduction of surgical instrumentation and endoscopes (or othervisualization tools). These access assemblies maintain the pressure forthe pneumoperitoneum, as they have one or more seals that adapt to thesurgical instrumentation. Typically, a “zero-seal” in the accessassembly seals the access assembly in the absence of a surgicalinstrument in the access assembly, and an instrument seal seals around asurgical instrument that has been inserted through the access assembly.

The breadth of surgical instrumentation on the market today requires arobust seal capable adjusting to multiple sizes and withstandingmultiple insertions of surgical instrumentation. Some of theinstrumentation can include sharp edges that can tear or otherwisedamage seals. Therefore, it would be beneficial to have an accessassembly with improved seal durability.

SUMMARY

An access assembly with an improved seal durability is provided. Theaccess assembly includes an instrument valve housing and a valveassembly. The instrument valve housing includes upper, lower, and innerhousing sections and defines a cavity. The valve assembly is disposedwithin the cavity of the instrument valve housing. The valve assemblyincludes a guard assembly, a seal assembly disposed adjacent to theguard assembly, and a centering mechanism for maintaining the sealassembly and guard assembly centered within the cavity of the instrumentvalve. The guard assembly includes a plurality of guard sections. Theseal assembly is disposed adjacent to the guard assembly, the sealassembly including a plurality of seal sections, the plurality of sealsections being movable from an unfolded configuration to foldedconfiguration in which the seal assembly forms a hexagonal memberdefining an opening to facilitate sealed passage of a surgicalinstrument.

In embodiments, an opening in the seal assembly has a diameter between0.025″ and 0.100″. The seal assembly may include six seal sections. Theplurality of seal sections may be formed of polyisoprenes or siliconeelastomers. Seal sections of the plurality of seal sections may beconnected to adjacent seal sections of the plurality of seal sections byconnector portions. The connector portions may include living hinges.Each seal section of the plurality of seal sections may include a wingshape.

In some embodiments, an inner edge of each seal section of the pluralityof seal sections is straight. Alternatively, the inner edge of each sealsection of the plurality of seal sections defines a V-shape. The V-shapemay include an angle between one hundred eighty degrees and two hundredseventy-five degrees. The inner edge of each seal section of theplurality of seal sections may be tapered. The plurality of sealsections may include first, second, third, fourth, fifth, and sixth sealsections. Each of the first, second, third, fourth, fifth, and sixthseal sections may overlap the adjacent second, third, fourth, fifth,sixth, and first seal sections.

The access assembly may further include a retainer assembly includingupper and lower retainer members. At least one of the upper and lowerretainer members may include a plurality of pins receivable through theguard assembly and seal assembly for retaining the guard and sealassemblies relative to each other. The centering mechanism may include abellows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosureand, together with a general description of the disclosure given above,and the detailed description of the embodiments given below, serve toexplain the principles of the disclosure, wherein:

FIG. 1 is a side perspective view of an access assembly according to anembodiment of the present disclosure;

FIG. 2 a side cross-sectional view of the access assembly shown in FIG.1 taken along section line 2-2;

FIG. 3 is an exploded perspective view of a valve assembly, including acentering mechanism, a guard assembly, a seal assembly, and a retainerassembly;

FIG. 4 is a perspective view of the seal assembly shown in FIG. 3;

FIG. 5 is a perspective view of the seal assembly shown in FIG. 3, in anunfolded configuration;

FIG. 6-11 are perspective views of the seal assembly shown in FIG. 3, insequential partially folded conditions;

FIG. 12 is a top perspective view of the valve assembly shown in FIG. 3;

FIG. 13 is a bottom perspective view of the valve assembly shown in FIG.3;

FIG. 14 is a top view of a seal assembly according to another embodimentof the present disclosure, in an initial or unfolded configuration;

FIG. 15 is a perspective side view of a section of the seal assemblyshown in FIG. 14;

FIG. 16 is a side cross-sectional view of a section the seal assemblyshown in FIG. 14 taken along section line 16-16 shown in FIG. 15;

FIG. 17 is a top view of the seal assembly shown in FIG. 14, in a foldedconfiguration.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are describedhereinbelow with reference to the accompanying drawings; however, it isto be understood that the disclosed embodiments are merely exemplary ofthe disclosure and may be embodied in various forms. Well-knownfunctions or constructions are not described in detail to avoidobscuring the present disclosure in unnecessary detail. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure. Like reference numerals refer to similar or identicalelements throughout the description of the figures.

As used herein, the term “distal” refers to that portion of theinstrument, or component thereof which is farther from the user whilethe term “proximal” refers to that portion of the instrument orcomponent thereof which is closer to the user.

Access assemblies with obturators are employed during minimally invasivesurgery, e.g., laparoscopic surgery, and provide for the sealed accessof surgical instruments into an insufflated body cavity, such as theabdominal cavity. The access assemblies of the present disclosureinclude an instrument valve housing mounted on a cannula tube, andinclude an obturator (not shown) inserted through the valve housing andcannula. The obturator can have a blunt distal end, or a bladed ornon-bladed penetrating distal end and can be used to incise theabdominal wall so that the access assembly can be introduced into theabdomen. The handle of the obturator can engage or selectively lock intothe instrument valve housing of the access assembly.

Access assemblies are employed to tunnel through an anatomicalstructure, e.g., the abdominal wall, either by making a new passagethrough the anatomical structure or by passing through an existingopening through the anatomical structure. Once the trocar assembly withthe obturator has tunneled through the anatomical structure, theobturator is removed, leaving the access assembly in place. Theinstrument valve housing of the access assembly includes valves thatprevent the escape of insufflation gases from the body cavity, whilealso allowing surgical instruments to be inserted into the cavity.

In various embodiments, a bladeless optical trocar obturator may beprovided that permits separation of tissue planes in a surgicalprocedure and visualization of body tissue fibers as they are beingseparated, thereby permitting a controlled traversal across a body wall.In other embodiments, the trocar obturator may be bladeless withoutbeing optical, e.g., without providing contemporaneous visualizationthereof through the distal tip of an obturator. The bladeless obturatormay be provided for the blunt dissection of the abdominal lining duringa surgical procedure.

Various trocar obturators suitable for use with the access assembly ofthe present disclosure are known and include, for example, bladed,bladeless, blunt, optical, and non-optical. For a detailed descriptionof the structure and function of exemplary trocar assemblies, includingexemplar trocar obturators and exemplar cannulas, please refer tocommonly owned PCT Publication No. WO 2016/186905 (“the '905publication”), the content of which is hereby incorporated by referenceherein in its entirety.

With initial reference now to FIG. 1, an access assembly according toaspects of the present disclosure is shown generally as access assembly100. The access assembly 100 includes a cannula 102 and an instrumentvalve housing 110 secured to the cannula 102. For a detailed descriptionof an exemplary access assembly, please refer to the '905 publication.

With reference to FIG. 2, the instrument valve housing 110 of the accessassembly 100 includes an upper housing section 112, a lower housingsection 114, and an inner housing section 116. The upper, lower, andinner housing sections 112, 114, 116 are configured to support a valveassembly 120 on a proximal end of the cannula 102. More particularly,the inner housing section 116 is secured between the upper and lowerhousing sections 112, 114, and the valve assembly 120 is receivedbetween the inner and lower housing sections 116, 114. The upper andlower housing section 112, 114 of the instrument valve housing 110 maybe selectively attachable to, and detachable from, the inner housingsection 116. The lower housing section 114 may be releasably orpermanently attached to a cannula tube 104 (FIG. 1) of the accessassembly 102. In embodiments, either or both of the upper and lowerhousing sections 112, 114 of the instrument valve housing 110 mayinclude knurls, indentations, tabs, or be otherwise configured tofacilitate engagement by a clinician.

The access assembly 100 may also include features for the stabilizationof the access assembly. For example, the distal end of the cannula tube104 may carry a balloon anchor or another expandable member that engagesthe abdomen from the interior side. For example, see commonly owned U.S.Pat. No. 7,300,448, the entire disclosure of which is herebyincorporated by reference herein. A feature on the opposite side of theabdominal wall may be used to further stabilize the access assembly,such as adhesive tabs or adjustable foam collars.

The upper, lower, and inner housing sections 112, 114, 116 of theinstrument valve housing 110 define a longitudinal passage 111 forreceipt of a surgical instrument (not shown). The valve assembly 120 issupported within the instrument valve housing 110 to provide sealedpassage of the surgical instrument through the access assembly 100.

With particular reference to FIGS. 2 and 3, the valve assembly 120supported in the instrument valve housing 110 (FIG. 2) includes acentering mechanism 130, a guard assembly 140, a seal assembly 160, anda retainer assembly 180. The centering mechanism 130 of the valveassembly 120 permits radial movement of the valve assembly 120 relativeto the instrument valve housing 110 when a surgical instrument isreceived through the valve assembly 120, and returns the valve assembly120 to a generally centered position once the surgical instrument iswithdrawn from within the instrument valve housing 110. The guardassembly 140 protects the seal assembly 160 during insertion andwithdrawal of a surgical instrument through the seal assembly 160. Theseal assembly 160 provides sealed passage of the surgical instrumentthrough the instrument valve housing 110. The retainer assembly 180maintains the centering mechanism 130, the guard assembly 140, and theseal assembly 160 in an aligned relationship with one another.

With continued reference to FIGS. 2 and 3, as noted above, the centeringmechanism 130 of the valve assembly 120 is configured to maintain thevalve assembly 120 centered within the instrument valve housing 110(FIG. 2). In embodiments, and as shown, the centering mechanism 130includes an outer annular ring 132, an inner annular ring 134, and abellows 136 disposed between the outer annular ring 132 and the innerannular ring 134. As shown in FIG. 2, the outer annular ring 132 isreceived between the inner housing section 116 and the lower housingsection 114 to retain the centering mechanism 130 within the instrumentvalve housing 110. The inner annular ring 134 supports the seal assembly160. For a detailed description of the structure and function of anexemplary centering mechanism, please refer to commonly owned U.S. Pat.No. 6,702,787 (“the '787 patent”), the content of which is incorporatedherein by reference in its entirety.

Although shown including the centering mechanism 130 having bellows 136,the valve assembly 120 may include alternative centering mechanisms. Forexample, the centering mechanism may include an annular base and aplurality of spokes extending from the base, as described in commonlyowned U.S. Pat. App. Pub. No. 2015/0025477 (“the '477 publication”), thecontent of which is incorporated herein by reference in its entirety. Itis envisioned that the centering mechanism may include multiple sets ofspokes, as disclosed in the '477 publication.

Still referring to FIGS. 2 and 3, the guard assembly 140 of the valveassembly 120 includes a ring portion 142 and first, second, third, andfourth petals 144, 146, 148, 150. The guard assembly 140 may be formedfrom a sheet of plastic/polymeric material by stamping with a tool thatforms the ring portion 142 and the petals 144, 146, 148, 150.Alternatively, the guard assembly 140 may be formed by molding or othertechniques. It is envisioned that the guard assembly may include anynumber of petals, and the petals may include flap portions of any sizeor configuration. See, for example, U.S. Pat. Nos. 5,895,377 and6,569,120 (“the '377 and '120 Patents”), and PCT Publication WO91/12838, the entire disclosures of which are hereby incorporated byreference herein, for exemplary guard assemblies, as well as otheraspects of access assemblies. For a detailed description of thestructure and function of exemplary guard assemblies, please refer tocommonly owned U.S. patent application Ser. Nos. 16/394,043, 16/238,823and 62/916,931, the content of which is incorporated herein by referencein its entirety.

With particular reference now to FIGS. 4-11, the seal assembly 160 ofthe valve assembly 120 is configured to provide a seal around an outersurface of a surgical instrument (not shown) passing through theinstrument valve housing 110 (FIG. 2).

The seal assembly 160 includes first, second, third, fourth, fifth, andsixth petals or sections 162, 164, 166, 168, 170, 172 movable from afirst or unfolded configuration (FIG. 5) to folded configuration (FIG.4). In the folded configuration, the seal assembly 160 forms asubstantially planar, hexagonal member, with the first, second, third,fourth, fifth, and sixth sections 162, 164, 166, 168, 170, 172 of theseal assembly 160 defining an opening 161 therebetween to facilitatesealed passage of a surgical instrument (not shown) through the sealassembly 160. In embodiments, the opening 161 is 0.025″ to 0.100″ indiameter. By forming the opening 161 out of the first, second, third,fourth, fifth, and sixth sections 162, 164, 166, 168, 170, 172 of theseal assembly 160 instead of as a continuous solid opening through assingle seal member, the likelihood of the seal assembly 160 tearingduring insertion, removal, and use of a surgical instrument therethroughis greatly reduced. Although shown including six (6) sections, it isenvisioned that the seal assembly 160 may include as few as four (4)sections, and as many as eight (8) sections.

The first, second, third, fourth, fifth, and sixth sections 162, 164,166, 168, 170, 172 of the seal assembly 160 are formed of an elasticmaterial, e.g., rubber, polyisoprenes, or silicone elastomers. Inembodiments, the first, second, third, fourth, fifth, and sixth sections162, 164, 166, 168, 170, 172 may include one or more fabric layers.

With particular reference to FIG. 5, the first and second sections 162,164 of the seal assembly 160, the second and third sections 164, 166,the third and fourth sections 166, 168, the fourth and fifth sections168, 170, and the fifth and sixth section 170, 172 are connected to oneanother by a connector portion 162 a, 164 a, 166 a, 168 a, 170 a,respectively. In embodiments, the connector portions 162 a, 164 a, 166a, 168 a, 170 a include a living hinge, or are otherwise formed tofacilitate folding of the sections.

An inner edge 162 b, 164 b, 166 b, 168 b, 170 b, 172 b of the respectivefirst, second, third, fourth, fifth, and sixth sections 162, 164, 166,168, 170, 172 of the seal assembly 160 may be straight (FIG. 14), or maydefine a V-shape (FIG. 5). In embodiments, the V-shape defines an anglebetween one-hundred eighty degrees (180°) and two-hundred seventy-fivedegrees (275°). The V-shape of the inner edges 162 b, 164 b, 166 b, 168b, 170 b facilitates reception of a surgical instrument (not shown)through the seal assembly 160.

Each of the first, second, third, fourth, fifth, and sixth sections 162,164, 166, 168, 170, 172 of the seal assembly 160 includes a wing-shapedbody that is configured to partially overlap the respective connectedsecond, third, fourth, fifth, and sixth sections 164, 166, 168, 170, 172when the seal assembly 160 is in the folded configuration. The first,second, third, fourth, fifth, and sixth sections 162, 164, 166, 168,170, 172 are also configured to partially overlap the respectiveadjacent third, fourth, fifth, sixth, first, and second sections 166,168, 170, 172, 162, 164 and the respective adjacent sixth, first,second, third, fourth, and fifth sections 172, 162, 164, 166, 168. Forexample, the first section 162 overlaps the connected second section164, and the adjacent third and sixth sections 166, 172. In this manner,a portion of each of the first, second, third, fourth, fifth, and sixthsections 162, 164, 166, 168, 170, 172 overlaps three sections.

Each of the first, second, third, fourth, fifth, and sixth sections 162,164, 166, 168, 170, 172 defines a plurality of openings 163, 165, 167,169, 171, 173 along an outer perimeter of each section 162, 164, 166,168, 170, 172. In embodiments, and as shown, the plurality of openings163, 165, 167, 169, 171, 173 are arranged such the first and last twoopenings of each plurality of openings 163, 165, 167, 169, 171, 173align with the last and first two openings of the adjacent sections. Forexample, as noted above, the first section 162 overlaps the connectedsecond section 164 and the adjacent third and sixth sections 166, 177.In this manner, the first two openings 163 a of the plurality ofopenings 163 align with last two openings 167 b of the plurality ofopenings 167 in the third section 166, and the second two openings 163 bof the plurality of openings 163 in the first section 162 align with thefirst two openings 173 of the plurality of openings 173 of the sixthsection when the seal assembly 160 is in the folded configuration.

The plurality of openings 163, 165, 167, 169, 171, 173 are configured toreceive pins 186 (FIG. 3) of the retainer assembly 180 to maintain theseal assembly 160 in the folded condition and to secure the sealassembly 160 relative to the guard assembly 140 and the centeringmechanism 130.

The method of folding the seal assembly 160 will now be described withreference to FIGS. 6-11. Referring initially to FIG. 6, the firstsection 162 of the seal assembly 160 is folded relative to the secondsection 164 at the hinge portion 162 a between the first and secondsections 162, 164, as indicated by arrow “A”, such that a portion of thefirst section 162 adjacent the hinge portion 162 a aligns with theportion of the second section 164 of the seal assembly 160 adjacent thehinge portion 162 a. In this manner, the plurality of openings 163 inthe portion of the first section 162 adjacent the hinge portion 162 aaligns with the plurality of openings 165 in the overlapping portion ofthe second section 164 of the seal assembly 260 adjacent the hingeportions 162 a.

Turning to FIG. 7, the second section 164 of the seal assembly 160 isfolded relative to the third section 166 at the hinge portion 164 abetween the second and third sections 164, 166, as indicated by arrow“B”, such that a portion of the second section 164 adjacent the hingeportion 164 a overlaps the length of the portion of the third section166 of the seal assembly 160 adjacent the hinge portion 164 a. In thismanner, the plurality of openings 165 in the portion of the secondsection 164 adjacent the hinge portion 164 a aligns with the pluralityof openings 167 in the overlapping portion of the third section 166 ofthe seal assembly 160 adjacent the hinge portions 164 a.

Referring to FIG. 8, the third section 166 of the seal assembly 160 isfolded relative to the fourth section 168 of the seal assembly 160 atthe hinge portion 166 a between the third and fourth sections 166, 168,as indicated by arrow “C”, such that the portion of the third section166 adjacent the hinge portion 166 a overlaps the portion of the fourthsection 168 of the seal assembly 260 adjacent the hinge portion 166 a.In this manner, the plurality of openings 167 in the portion of thethird section 166 adjacent the hinge portion 166 a aligns with theplurality of openings 169 in the overlapping portion of the fourthsection 168 of the seal assembly 160 adjacent the hinge portions 166 a.

With reference to FIG. 9, the fourth section 168 of the seal assembly160 is folded relative to the fifth section 170 of the seal assembly 160at the hinge portion 168 a between the fourth and fifth sections 168,170, as indicated by arrow “D”, such that the portion of the fourthsection 168 adjacent the hinge portion 168 a overlaps the portion of thefifth section 170 of the seal assembly 160 adjacent the hinge portion168 a. In this manner, the plurality of openings 169 in the portion ofthe fourth section 168 adjacent the hinge portion 168 a aligns with theplurality of openings 171 in the overlapping portion of the fifthsection 170 adjacent the hinge portion 168 a.

Turning to FIG. 10, the fifth section 170 of the seal assembly 160 isfolded relative to the sixth section 172 at the hinge portion 170 abetween the fifth and sixth sections 170, 172, as indicated by arrow“E”, such that the portion of the fifth section 170 adjacent the hingeportion 170 a overlaps the portion of the sixth section 172 of the sealassembly 260 adjacent the hinge portion 170 a. In this manner, theplurality of openings 171 in the portion of the fifth section 170adjacent the hinge portion 170 a aligns with the plurality of openings173 in the overlapping portion of the sixth section 170 of the sealassembly 160 adjacent the hinge portion 170 a.

In embodiments, a portion of the sixth section 172 of the seal assembly160 is inserted under the first section 162 of the seal assembly 160 tointerweave the first and sixth sections 162, 172. This interweavingincreases the integrity of the seal assembly 160.

Referring back to FIGS. 2 and 3, the retainer assembly 180 of the valveassembly 120 is configured to secure the guard assembly 140 relative tothe seal assembly 160, and secure the guard and seal assemblies 140, 160to the centering mechanism 130. The retainer assembly 180 includes theupper retainer member 182, and a lower retainer member 184.

As noted above, the upper retainer member 182 includes a plurality ofpins 186. The plurality of pins 186 extend from a bottom surface of theupper retainer member 182. Each pin of the plurality of pins 186 isconfigured to be lockingly received within an opening of a plurality ofopenings 185 (FIG. 3) of the lower retainer member 184. In embodiments,the plurality of pins 186 is welded, glued, adhered, bonded or otherwisesecured within the plurality of openings 185 in the lower retainermember 184 to secure the upper retainer member 182 and the lowerretainer member 184 together. Alternatively, the lower retainer member184 may instead, or additionally, include a plurality of pins (notshown) with the upper retainer member 182 defining a pluralitycorresponding openings (not shown). Either or both of the upper andlower retainer members 182, 184 may include locking features (not shown)for engaging the plurality of pins and securing the upper retainermember 182 to the lower retainer member 184.

With particular reference to FIG. 2, the plurality of pins 186 of theupper retainer member 182 extend through the ring portion 142 of theguard assembly 140, through the seal assembly 160, through the innerannular ring 134 of the centering mechanism 130, and into the openings185 in the lower retainer member 184.

During a surgical procedure utilizing access assembly 100, a surgicalinstrument (not shown) is introduced into the instrument valve housing110 through the longitudinal passage 111 in the upper, lower, and innerhousing sections 112, 114, 116. As described in the '377 and '120Patents, the distal end of the surgical instrument engages the petals144, 146, 148, 150 (FIG. 3) of the guard assembly 140 causing therespective petals 144, 146, 148, 150 to flex downward into contact withthe seal assembly 160 to cause the central opening 163 of the sealassembly 162 to open to accommodate passage of the surgical instrumentthrough the seal assembly. The guard assembly 130 minimizes damage tothe seal assembly 160 during insertion of an instrument through thevalve assembly 120. The guard assembly 130 operates to protect the seal162 of the seal assembly 160 from tearing or other damage as a surgicalinstrument is received through and withdrawn from the seal assembly 160.As discussed above, the multi-petal configuration of the seal assembly160 reduces the likelihood of the seal assembly 160 tearing duringinsertion and/or removal of the surgical instrument therethrough.

With reference now to FIGS. 14-17, a seal assembly according to anotherembodiment of the present disclosure is shown generally as seal assembly260. The seal assembly 260 is substantially similar to the seal assembly160 (FIGS. 4-11) described hereinabove, and will only be described indetail as relates to the differences therebetween.

The seal assembly 260 is configured to provide a seal around an outersurface of a surgical instrument (not shown) passing through theinstrument valve housing 110 (FIG. 2). The seal assembly 260 includesfirst, second, third, fourth, fifth, and sixth petals or sections 262,264, 266, 268, 270, 272 foldable from a first or unfolded configuration(FIG. 14) to folded configuration (FIG. 17). In the folded configurationthe seal assembly 260 forms a substantially planar, hexagonal member,with the first, second, third, fourth, fifth, and sixth sections 262,264, 266, 268, 270, 272 of the seal assembly 260 defining an opening 261therebetween to facilitate sealed passage of a surgical instrument (notshown) through the seal assembly 260.

An inner edge 262 b, 264 b, 266 b, 268 b, 270 b, 272 b of the respectivefirst, second, third, fourth, fifth, and sixth sections 262, 264, 266,268, 270, 272 of the seal assembly 160 are tapered. The tapered inneredge 262 b, 266 b, 270 b of the first, third, and fifth sections 262,266, 270, respectively, is disposed on a first surface 262′, 266′, 270′(FIG. 17) of the respective first, third, and fifth sections 262, 266,270 sections, and the tapered inner edge 264 b, 268 b, 272 b of thesecond, fourth, and sixth sections 264, 268, 274, respectively, isdisposed on a second surface 264″, 268″, 272″ of the respective first,third, and fifth sections 262, 266, 270 sections. The tapered inner edge262 b, 264 b, 266 b, 268 b, 270 b, 272 b of the respective first,second, third, fourth, fifth, and sixth sections 262, 264, 266, 268,270, 272 facilitates sealed receipt of a surgical instrument through theopening 261 in the seal assembly 260.

The seal assembly 260 is secured within the instrument valve housing 110(FIG. 2) in a similar manner to seal assembly 160 (FIGS. describedhereinabove. The seal assembly 260 operates in a similar manner to sealassembly 160.

While various embodiments of the present disclosure have been shown anddescribed herein, it will be obvious to those skilled in the art thatthese embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the present disclosure. Accordingly,it is intended that the invention be limited only by the spirit andscope of the appended claims.

The invention claimed is:
 1. An access assembly comprising: aninstrument valve housing including upper, lower, and inner housingsections and defining a cavity; and a valve assembly disposed within thecavity of the instrument valve housing, the valve assembly including: aguard assembly including a plurality of guard sections, a seal assemblydisposed adjacent to the guard assembly, the seal assembly including aplurality of seal sections, the plurality of seal sections being movablefrom an unfolded configuration to a folded configuration in which theseal assembly forms a hexagonal member defining an opening to facilitatesealed passage of a surgical instrument; and a centering mechanism formaintaining the seal assembly and guard assembly centered within thecavity of the instrument valve.
 2. The access assembly of claim 1,wherein the opening in the seal assembly has a diameter between 0.025″and 0.100″.
 3. The access assembly of claim 1, wherein the seal assemblyincludes six seal sections.
 4. The access assembly of claim 1, whereinthe plurality of seal sections are formed of polyisoprenes or siliconeelastomers.
 5. The access assembly of claim 1, wherein seal sections ofthe plurality of seal sections are connected to adjacent seal sectionsof the plurality of seal sections by connector portions.
 6. The accessassembly of claim 5, wherein the connector portion includes livinghinges.
 7. The access assembly of claim 1, wherein each seal section ofthe plurality of seal sections includes a wing shape.
 8. The accessassembly of claim 1, wherein an inner edge of each seal section of theplurality of seal sections is straight.
 9. The access assembly of claim1, wherein an inner edge of each seal section of the plurality of sealsections defines a V-shape.
 10. The access assembly of claim 9, whereinthe V-shape includes an angle between 180 degrees and 275 degrees. 11.The access assembly of claim 1, wherein an inner edge of each sealsection of the plurality of seal sections is tapered.
 12. The accessassembly of claim 1, wherein the plurality of seal sections includesfirst, second, third, fourth, fifth, and sixth seal sections, each ofthe first, second, third, fourth, fifth, and sixth seal sectionsoverlapping the adjacent second, third, fourth, fifth, sixth, and firstseal sections.
 13. The access assembly of claim 1, further including aretainer assembly including upper and lower retainer members.
 14. Theaccess assembly of claim 13, wherein at least one of the upper and lowerretainer members includes a plurality of pins receivable through theguard assembly and seal assembly for retaining the guard and sealassemblies relative to each other.
 15. The access assembly of claim 1,wherein the centering mechanism includes a bellows.